JP3705143B2 - Spread spectrum transmitter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spread spectrum transmitter using a spread spectrum system.
[0002]
[Prior art]
Hereinafter, an outline of an RF unit of a car phone using a conventional spread spectrum system will be described with reference to FIG. Here, the transmitter performs single code transmission. Hereinafter, the transmitter is referred to as a single code transmitter.
[0003]
The single code transmitter includes an attenuator 1, a power amplifier 2, a directional coupler 3, a terminator 4a, a detector (diode) 4b, a filter 5, an A-D converter 6, a microcomputer 7, a memory (non-volatile memory). ) 7a, a DA converter 8 and an operational amplifier 9.
[0004]
The attenuator 1 uses the modulated high-frequency signal as an input signal, attenuates the input signal by a predetermined attenuation amount, and outputs the amplified signal. The power amplifier 2 amplifies the output signal of the attenuator 1 with a preset gain, A transmission output signal is supplied to the antenna end side. The antenna end is an antenna mounting portion of a car phone.
[0005]
The directional coupler 3 is provided at the subsequent stage of the power amplifier 2, and the directional coupler 4 has one end connected to the terminator 4 a and the other end connected to the detector 4 b. The detector 4b receives a proportional signal having a voltage level proportional to the transmission output signal, and the detector 4b outputs a detection signal indicating the envelope level in the positive half wave of the proportional signal.
[0006]
The filter 5 smoothes the detection signal of the detector 4b and outputs a smooth signal. As described above, the detector 4 b performs power detection of the transmission output signal together with the filter 5.
[0007]
The A-D converter 6 performs analog-digital conversion on the smooth signal of the filter 5 and outputs a digital signal. The memory 7a has a transmission power map in advance, and the transmission power map holds transmission power data (for example, 75) for each target transmission power level. However, the target transmission power level (the target value of the power of the transmission output signal) is obtained from the power control signal from the communication network side.
[0008]
Further, the microcomputer 7 selects transmission power data corresponding to the target transmission power level from the transmission power map of the memory 7a, obtains a difference between the transmission power data and the digital signal from the A / D converter 6, A difference signal corresponding to the difference is output.
[0009]
The DA converter 8 performs digital-analog conversion on the differential signal from the microcomputer 7 and outputs an analog signal to the attenuator 1. The attenuator 1 converts the input signal into a predetermined attenuation amount corresponding to the analog signal. Only attenuated output.
[0010]
That is, the attenuation amount of the attenuator 1 is controlled by the microcomputer 7 so as to be a constant level according to the target transmission power level. Hereinafter, the transmission power map of the memory 7a will be described.
[0011]
At the time of transmission by the single code transmitter, the attenuation amount of the attenuator 1 differs for each target transmission power level. Further, the passage loss and attenuation characteristics of the attenuator 1 and the power gain of the power amplifier are different for each car phone product. In addition to this, the temperature change characteristic (for example, due to heat generation) of the power gain with respect to the target transmission power level is different for each car phone product.
[0012]
For this reason, at the time of manufacture of the automobile phone, each transmission power data corresponding to each target transmission power is stored in the transmission power map of the memory 7a for each product. Thereby, the single code transmitter can accurately control the transmission power so as to keep the target transmission power level constant.
[0013]
[Problems to be solved by the invention]
Recently, spread spectrum communication for performing multicode transmission has been proposed, and the present inventor has proposed a mobile phone (wireless communication terminal) using a spread spectrum system (3GPP / W-CDMA system) for performing multicode transmission. The transmitter was examined based on the single code transmitter.
[0014]
Hereinafter, a mobile phone transmitter (hereinafter simply referred to as a multi-code transmitter) using a spread spectrum system that performs multi-code transmission as studied by the present inventor will be described with reference to FIGS.
[0015]
As shown in FIG. 7, the multi-code transmitter includes a digital modulator 10a, generators 10b to 10d, a power controller 10e, a power map 10f, a DA converter 10g, multipliers 11 to 18, an adder 20, 21, multipliers 30 and 31, phase shifter 32, digital filters (FIR) 33 and 34, local oscillator (Lo) 35 A quadrature modulator 40 with a variable gain amplifier, and a band-pass filter 50.
[0016]
The quadrature modulator with variable gain amplifier 40 includes multipliers 41 and 42, a phase shifter 43, an adder 44, and a gain control amplifier 45.
[0017]
As shown in FIG. 8, the multi-code transmitter includes a local oscillator (Lo) 36, a band pass filter 51, a multiplier 52, a gain control amplifier 60, a band pass filter 70, an amplifier 80, a directional coupler 90, An isolator 91, a duplexer 92, an antenna 93, a detector 100, a filter 110, and an A-D converter 120 are provided.
[0018]
In FIG. 7, a digital modulator 10a digitally modulates communication data and outputs first to third transmission signals (DPDCH1 to DPDCH3). The digital modulator 1 outputs a control signal (DPCCH). As the modulation method of digital modulation, 16QAM, 64QAM, etc. are adopted, and the selection of the modulation method varies depending on the status of communication traffic and the number of users. Et Instructed.
[0019]
Further, the transmission rates of the first to third transmission signals are each a variable rate and the same rate. The control signal has a synchronization signal for synchronizing the automobile telephone and the communication network side (base station), and the rate of the control signal is a fixed rate.
[0020]
Note that DPDCH is an abbreviation for dedicated Physical Data Channel1. DPCCH is an abbreviation for dedicated physical control channel.
[0021]
In the example illustrated in FIG. 10, the number of transmission signals (DPDCH1 to DPDCH3) (hereinafter referred to as the number of channels) is “four”, but the number of transmission signals (DPDCH) output from the digital modulator 1 is Change. Specifically, (1) the first to third transmission signals are stopped, and only the control signal is output. (2) The output of the second and third transmission signals is stopped, and only the first transmission signal and the control signal are output. (3) The output of the third transmission signal is stopped, and only the first and second transmission signals and the control signal are output. (4) All of the first to third transmission signals and the control signal are output.
[0022]
Thus, in a multicode transmitter, only the control signal is always Out However, at least one transmission signal (DPDCH) is selectively output or stopped. Hereinafter, an example in which all of the first to third transmission signals and the control signal are output in the multicode transmitter will be described.
[0023]
The multiplier 11 spreads the spectrum of the first transmission signal with the first spreading code (Cd1) and outputs the first spread signal. The multiplier 12 multiplies the first spread signal by the first gain parameter βd (first coefficient) and outputs a first multiplication signal.
[0024]
The multiplier 13 spectrum-spreads the third transmission signal with the third spreading code (Cd3) and outputs a third spread signal. The multiplier 14 multiplies the third spread signal by the first gain parameter βd (first coefficient) and outputs a third multiplication signal. The adder 20 adds the first and third multiplication signals and outputs a first addition signal. Note that Cd is an abbreviation for Channelization Code.
[0025]
The multiplier 15 spreads the spectrum of the second transmission signal with the second spreading code (Cd2) and outputs the second spread signal. The multiplier 16 multiplies the second spread signal by the first gain parameter βd (first coefficient) and outputs a second multiplication signal.
[0026]
The multiplier 17 spreads the control signal with the fourth spreading code (Cc) and outputs a fourth spread signal. The multiplier 18 multiplies the second spread signal and the second gain parameter βc (second coefficient) and outputs a fourth multiplication signal. The adder 21 adds the second and fourth multiplication signals and outputs a second addition signal.
[0027]
The first to fourth spreading codes are generated by the generator 10b, and the first and second gain parameters βd and βc are generated by the generator 10c.
[0028]
Next, the first and second gain parameters βd and βc will be described. First, a receiver of a base station of a communication network receives a transmission signal from a car phone and performs despreading processing on the first to fourth multiplication signals based on this transmission signal. In despreading the first multiplication signal, the second to fourth multiplication signals become interference signals, and in despreading the second multiplication signal, the first, third, and fourth multiplication signals are interference signals. It becomes.
[0029]
Similarly, when despreading the third multiplication signal, the first, second, and fourth multiplication signals become interference signals, and when despreading the fourth multiplication signal, the first to third multiplication signals are It becomes a disturbing signal.
[0030]
For this reason, if the power of each of the first to fourth multiplication signals is not uniform, it is difficult to perform the despreading process of each of the first to fourth multiplication signals satisfactorily. Here, since the power of the fourth spread signal is constant because the rate of the control signal is a fixed rate, each of the first to third transmission signals has a variable rate as described above. Each power of the spread signals 1 to 3 changes according to a change in rate.
[0031]
Therefore, the first and second gain parameters βd and βc are set so that the sum of each power of the first to fourth multiplication signals (bit energy per bit of the first to fourth multiplication signals) is kept constant. The respective powers of the first and fourth multiplication signals (the bit energy per bit of the first multiplication signal and the bit energy per bit of the fourth multiplication signal) are matched.
[0032]
Accordingly, as described above, since the rates of the first to third transmission signals are the same, the respective powers of the first to fourth multiplication signals match. As described above, since the respective powers of the first to fourth multiplication signals are matched, the despreading processing of each of the first to fourth multiplication signals can be satisfactorily performed in the receiver of the base station of the communication network. .
[0033]
The multiplier 30 multiplies the first addition signal from the adder 20 by the long code. The long code is a scramble code and is a unique code for each automobile telephone (wireless communication terminal), and serves to identify the automobile telephone on the communication network side. The scramble code may be a short code instead of the long code. The scramble code is generated by the generator 10d.
[0034]
The digital filter (FIR) 33 receives the output signal from the multiplier 30 and outputs a filter signal. The phase shifter 32 receives the long code and outputs an output signal obtained by shifting the phase of the long code by 90 °. The multiplier 31 outputs the second addition signal from the adder 21 to the second addition signal from the phase shifter 32. Is multiplied by the output signal of. The digital filter (FIR) 34 receives the output signal from the multiplier 31 and outputs a filter signal.
[0035]
Here, in the quadrature modulator 40 with variable gain amplifier, the filter signal from the digital filter (FIR) 33 is input as the real component I, and the filter signal from the digital filter (FIR) 34 is input as the imaginary component Q. Then, quadrature modulation is performed based on filter signals from both digital filters (FIR) 33 and 34.
[0036]
Specifically, the multiplier 41 multiplies the filter signal from the digital filter (FIR) 33 and the carrier wave signal from the local oscillator (Lo) 35. That is, the multiplier 41 converts the filter signal of the digital filter 33 into a signal having a higher frequency than the filter signal. The phase shifter 43 receives the carrier signal from the local oscillator (Lo) 35 and outputs a phase shift carrier signal obtained by shifting the phase of the carrier signal by 90 °.
[0037]
The multiplier 42 multiplies the filter signal from the digital filter (FIR) 34 and the phase shift carrier signal from the phase shifter 43. The adder 44 adds the output signals from the multipliers 41 and 42 and outputs the added signal as a quadrature modulation signal. The gain control amplifier 45 power-amplifies the quadrature modulation signal (addition signal) with a variable gain corresponding to the analog signal from the DA converter 10g, and outputs a transmission output signal.
[0038]
The bandpass filter 50 receives the transmission output signal of the gain control amplifier 45 and outputs a filter signal. The multiplier 52 multiplies the filter signal of the bandpass filter 50 and the frequency signal from the local oscillator (Lo) 36. .
[0039]
That is, the multiplier 52 converts the filter signal of the bandpass filter 50 into a signal having a higher frequency than that of the filter signal. The band pass filter 51 receives the output signal from the multiplier 52 and outputs a filter signal. The gain control amplifier 60 amplifies the power of the filter signal of the bandpass filter 51 with a variable gain corresponding to the digital signal from the DA converter 10g, and outputs an amplified signal.
[0040]
The band pass filter 70 receives the amplified signal from the gain control amplifier 60 and outputs a filter signal. The amplifier 80 amplifies the power of the filter signal from the bandpass filter 70 with a preset gain. An output signal of the amplifier 80 is output to the antenna 93 through the directional coupler 90, the isolator 91, and the duplexer 92. Thereby, the output signal of the amplifier 80 is output using radio waves as a medium.
[0041]
The detector 100 receives the output proportional signal from the directional coupler 90, and the detector 100 outputs a detection signal (DC voltage) indicating the envelope level of the positive half wave of the output proportional signal. The filter 110 smoothes the detection signal of the detector 100 and outputs a smooth signal. The AD converter 120 performs analog-digital conversion on the smooth signal from the filter 110 and outputs a digital signal.
[0042]
In FIG. 7, the memory (transmission power map) 10f holds transmission power data for each target transmission power instructed from the base station, and the power controller 10e transmits the transmission power data of the memory 10f and the A / D conversion. A control signal is output in response to the digital signal from the device 120.
[0043]
The DA converter 10g converts the control signal from the power controller 10e from digital to analog, and outputs an analog signal to the gain control amplifiers 45 and 60. Thereby, the gain control amplifiers 45 and 60 set the power of the transmission output signal to the target transmission power level according to the control signal from the power controller 10e. In Controlled to keep.
[0044]
Hereinafter, transmission power data of the memory 10f will be described. In the single code transmitter described above, a voltage waveform (see B in FIG. 9) corresponding to the target transmission power level is obtained as the detection signal of the detector 4b. A DC voltage waveform corresponding to is obtained.
[0045]
Here, the transmission power control requires a digital signal after A / D conversion in a smooth signal and transmission power data for each target transmission power level. That is, the memory 7a is provided with only one type of transmission power map having transmission power data for each target transmission power level.
[0046]
However, according to the study by the present inventor, it has been found that a multi-code transmitter requires a plurality of types of transmission power maps as the transmission power map of the memory 10f. As shown in FIGS. 10 and 11, the amplitude levels of the first to fourth multiplication signals (see D1 to D4 in FIG. 10) change according to changes in the first and second gain parameters βd and βc. To do. For this reason, the voltage waveform of the amplified signal of the gain control amplifier 60 (see symbol C) changes, and the voltage waveform of the detection signal of the detector 100 (see E in FIG. 10) changes.
[0047]
In the example shown in FIG. 11, the amplitude level of the first to third multiplication signals changes from DL in FIG. 10 to DL ′ in FIG. 11, and the amplitude level of the fourth multiplication signal in FIG. It changes from DR to DR ′ in FIG.
[0048]
Therefore, the amplitude level of the amplified signal of the gain control amplifier 60 changes from CL1 to CL3 in FIG. 10 to CL1 ′ to CL3 ′ in FIG. 11, and the amplitude level of the detection signal of the detector 100 is EL1 to EL3 in FIG. 11 to EL1 ′ to EL3 ′ in FIG.
[0049]
Next, a specific example in which the detection signal of the detector 100 changes due to changes in the first and second gain parameters βd and βc will be described.
[0050]
First, an example in which all of the first to third transmission signals and the control signal are output will be described. Here, as described above, the first and second gain parameters βd and βc set the powers of the first to fourth multiplication signals while keeping the total power of the first to fourth multiplication signals constant. Set to match. The maximum values of the first and second gain parameters βd and βc are “1”.
[0051]
For example, when the rate of the control signal is 15 Kbps and the rates of the first to third transmission signals are 120 Kbps, the first gain parameter is used to match the powers of the first to fourth multiplication signals. βd is “0.32”, and the second gain parameter βc is “0.04”.
[0052]
When the rates of the first to third transmission signals change from 120 Kbps to 240 Kbps, as described above, the first to fourth multiplications are performed while keeping the total power of the first to fourth multiplication signals constant. In order to match the powers of the signals, the first gain parameter βd is “0.326” and the second gain parameter βc is “0. 0 22 ".
[0053]
Also in the above-described digital modulator 10a, one of the plurality of digital modulation modulation schemes is selected by an instruction from the base station side. For this reason, when the modulation method changes, the rates of the first to third transmission signals change, so the combination of the first and second gain parameters βd and βc needs to be changed.
[0054]
As described above, when the rates of the first to third transmission signals change, the first and second gain parameters βd and βc change. Here, since the voltage waveform of the amplified signal of the gain control amplifier 60 is based on the sum of the first to fourth multiplication signals (see D1 to D4 in FIG. 10), the voltage waveform of the amplified signal is the first To change based on the change of the third transmission signal.
[0055]
That is, even if the average transmission power transmitted from the antenna 93 remains constant, the voltage waveform of the amplified signal changes depending on the combination of the first and second gain parameters βd and βc as described above. The voltage waveform of 100 detection signals (see E in FIG. 10) varies with the combination of the first and second gain parameters βd and βc together with the voltage waveform after the filter 110 is smoothed.
[0056]
Therefore, it is necessary to prepare a plurality of transmission power maps corresponding to the combination of the first and second gain parameters βd and βc. Further, the transmission power map needs to be prepared corresponding to the number of channels {number of transmission signals (DPDCH)}.
[0057]
However, when any of the first to third transmission signals is stopped, a multiplication signal corresponding to the input transmission signal (DPDCH) (hereinafter referred to as a corresponding multiplication signal), a fourth multiplication signal, The first and second gain parameters βd and βc are set so as to keep the sum of the respective powers constant and to make the powers of both the corresponding multiplication signal and the fourth multiplication signal coincide. Further, the input transmission signal has a variable rate of the same value as described above.
[0058]
For example, (1) when the output of the first to third transmission signals is stopped and only the control signal (rate: 15 Kbps) is output, the second gain parameter βc becomes “1”. (2) When the output of the second and third transmission signals is stopped and only the first transmission signal (rate: 120 Kbps) and the control signal (rate: 15 Kbps) are output, the first and second gain parameters βd, βc is set such that the sum of the powers of the first and fourth multiplication signals is constant and the powers of the first and fourth multiplication signals are made to match, so the first gain parameter βd is “0”. .8 ”and the second gain parameter βc is“ 0.2 ”.
[0059]
(3) When the output of the third transmission signal is stopped and only the first and second transmission signals (rate: 120 Kbps) and the control signal (rate: 15 Kbps) are output, the first and second gain parameters βd, βc is set so that the sum of the powers of the first, second, and fourth multiplication signals is constant, and the powers of the first, second, and fourth multiplication signals are set to coincide with each other. The gain parameter βd is “0.445”, and the second gain parameter βc is “0.11”.
[0060]
(4) When all of the first to third transmission signals (rate: 120 Kbps) and the control signal (rate: 15 Kbps) are output, the first and second gain parameters βd and βc are The sum of the powers of the multiplication signals is constant, the powers of the first to fourth multiplication signals are set to coincide with each other, the first gain parameter βd is “0.32”, and the second gain parameter βc is “0.04”.
[0061]
In this way, when the number of channels is “4”, there are four ways (1) to (4), and depending on the rates of the first to third transmission signals, the first and second channels are changed every four ways. The combination of gain parameters βd and βc changes. Therefore, even if the average transmission signal power transmitted from the antenna 93 remains constant, the voltage waveform obtained by smoothing the voltage waveform of the detection signal of the detector 100 by the filter 110 is the first and second gain parameters βd, Since it varies depending on the combination of βc, it is necessary to prepare a transmission power map corresponding to the number of channels.
[0062]
As described above, it is necessary to prepare a transmission power map corresponding to the combination of the first and second gain parameters βd and βc in addition to the number of channels.
[0063]
Specifically, if the first and second gain parameters βd and βc are 16 and the number of channels is 4, 64 types of transmission power maps are required (16 × 4 = 64). .
[0064]
That is, as shown in FIG. 12, assuming that 75 transmission power data are held in one transmission power map {24 dBm to −50 dBm (in the case of 1 dBm step)}, 4800 transmission power data are stored. This is necessary, and the memory 10f requires an excessive capacity.
[0065]
An object of the present invention is to provide a spread spectrum transmitter that suppresses an increase in data retention capacity.
[0066]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, in the first aspect of the invention, at least one transmission signal having a variable rate is spectrum-spread with a transmission code to output a transmission spread signal. 1 Spreading means (11, 13, 15), a second spreading means (17) for spectrally spreading a fixed-rate control signal with a control code and outputting a control spread signal, and a first coefficient for the transmission spread signal A first multiplication means (12, 14, 16) for multiplying the transmission multiplication signal by multiplication; a second multiplication means (18) for multiplying the control spread signal by the second coefficient to obtain a control multiplication signal; A setting means (10c) for setting the first and second coefficients so that the powers of the multiplication signal and the control multiplication signal are kept constant and matching the powers, and the transmission multiplication signal and the control multiplication signal are orthogonal to each other. Orthogonal modulation means (41 to 44) for modulating and outputting an orthogonal modulation signal; transmission output variable means (45, 60) for amplifying the orthogonal modulation signal with variable gain and outputting a transmission output signal; A memory (10k) that stores a transmission power map when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a fixed number; The power level of the transmission output signal is detected at each timing when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a constant number. Of transmit power map And updating means (10h) for updating the variable gain so as to approach the target value.
[0067]
Here, at the timing when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a constant number, the power level of the transmission output signal becomes a value corresponding to the target value. Only one type of transmission power map may be used for each transmission power data corresponding to the above, and an increase in the storage capacity of data indicating the target value can be suppressed.
[0068]
Specifically, as in the invention described in claim 2, the updating means Power level detection timing The output of the transmission signal may be prohibited and the timing at which only the control signal is output may be set. As in the invention according to claim 3, the updating means Power level detection timing As an alternative, the timing at which the digital modulation schemes of the transmission signals are the same may be set.
[0069]
According to the fourth aspect of the present invention, first spreading means (11, 13, 15) for spectrum-spreading at least one transmission signal having a variable rate with a transmission code to output a transmission spread signal, and control of a fixed rate A second spreading means (17) for spectrum-spreading the signal with a control code and outputting a control spread signal; and a first multiplying means (12, 12) for obtaining a transmission multiplication signal by multiplying the transmission spread signal by a first coefficient. 14, 16), the second multiplication means (18) for obtaining the control multiplication signal by multiplying the control spread signal by the second coefficient, and keeping the total power of the transmission multiplication signal and the control multiplication signal constant. , Setting means (10c) for setting the first and second coefficients so as to match each power, and orthogonal modulation means (41-44) for orthogonally modulating the transmission multiplication signal and the control multiplication signal to output an orthogonal modulation signal ) And straight Transmission output variable means (45, 60) that amplifies the modulated signal with variable gain and outputs a transmission output signal, the variable rate is a constant rate, and the number of transmissions of the control signal and the transmission signal is a fixed number. Updating means (10h) for detecting the power level of the transmission output signal at each timing and updating the variable gain so that the power level approaches the target value. The timing at which the digital modulation schemes of the transmission signals are the same is set. Also, According to the fifth aspect of the present invention, there is provided a first method in which at least one transmission signal having a variable rate is spectrum-spread with a transmission code to output a transmission spread signal. 1 Spreading means (11, 13, 15), a second spreading means (17) for spectrally spreading a fixed-rate control signal with a control code and outputting a control spread signal, and a first coefficient for the transmission spread signal A first multiplication means (12, 14, 16) for multiplying the transmission multiplication signal by multiplication; a second multiplication means (18) for multiplying the control spread signal by the second coefficient to obtain a control multiplication signal; A setting means (10c) for setting the first and second coefficients so that the powers of the multiplication signal and the control multiplication signal are kept constant and matching the powers, and the transmission multiplication signal and the control multiplication signal are orthogonal to each other. Orthogonal modulation means (41 to 44) for modulating and outputting a quadrature modulation signal, and transmission output variable means (45, 60) for amplifying the orthogonal modulation signal with variable gain and outputting a transmission output signal, Setting the first and second coefficients is prohibited At the prohibited timing, the quadrature modulation means outputs a frequency signal having a constant frequency as a quadrature modulation signal to the transmission output variable means, detects the power level of the transmission output signal at each prohibition timing, and varies according to this power level. It has the update means (10h) which updates a gain, It is characterized by the above-mentioned.
[0070]
Thus, since the variable gain is updated at the prohibition timing at which the setting of the first and second coefficients is prohibited, the power level of the transmission output signal is set to the first and second coefficients when updating the variable gain. Will not change. Therefore, it is not necessary to prepare a target value indicating the power level in response to changes in the settings of the first and second coefficients, and an increase in the storage capacity of data indicating the target value can be suppressed.
[0071]
Specifically, the claims 7 As described in the invention, the first multiplication means outputs the transmission spread signal at a constant level at the inhibition timing, and the second multiplication means outputs the control spread signal at the constant level at the inhibition timing. May be.
[0072]
Also, Claim 8 Like the invention described in Further The new means may update the variable gain at each timing when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a constant number.
[0073]
Claims 6 In the invention described in (1), the antenna (93) that transmits the transmission output signal using radio waves as a medium and the switch means (130, 140) that cuts off or connects the front of the antenna are provided, and the update means is at the prohibition timing. The switch means is controlled to cut off the output to the antenna. Thereby, it is possible to prevent the transmission output signal from the antenna from being transmitted as a medium at the prohibition timing.
[0074]
Incidentally, the reference numerals in parentheses of the above means are examples that show the correspondence with the specific means described in each embodiment described later.
[0075]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 and 2 show a first embodiment of a multi-code communication device according to the present invention. FIG. 1 is a block diagram showing a part of the electric circuit configuration of the multicode transmitter, and FIG. 2 is a block diagram showing the rest of the electric circuit configuration of the multicode transmitter.
[0076]
In FIG. 1, a power controller 10h is provided in place of the power controller 10e shown in FIG. 7, and in FIG. 2, relays 130 and 140 are added to the configuration shown in FIG. Other configurations are substantially the same as those in FIGS.
[0077]
In FIG. 1, the power controller 10 h updates the variable gains of the gain control amplifiers 45 and 60 and drives the relays 130 and 140. The relay 130 is connected between the amplifier 80 and the directional coupler 90, and the fixed contact 131 of the relay 130 is connected to the output terminal of the amplifier 80.
[0078]
The first movable contact 132 of the relay 130 is connected to the input terminal 9 of the directional coupler 90. 0 The second movable contact 133 of the relay 130 is connected to the first movable contact 142 of the relay 140. The second movable contact 143 of the relay 140 is connected to the detection terminal 90 a of the directional coupler 90, and the first of the relay 140 is connected. Fixed The contact 141 is connected to the input terminal of the detector 100.
[0079]
Next, the operation of the first embodiment is illustrated. 3 Will be described. Figure 3 These are timing charts of the first to third transmission signals (UP-LINK DPDCH) and the control signal (UP-LINK DPCCH).
[0080]
First, the power controller 10h outputs a drive signal (RL1) to the relay 130, and the output terminal of the amplifier 80 and the input terminal of the directional coupler 90. 90b Connect between the two. At the same time, the power controller 10h outputs a drive signal (RL2) to the relay 140 to connect between the detection terminal 91 of the directional coupler 90 and the input terminal of the detector 100.
[0081]
Therefore, the output signal of the amplifier 80 is output to the antenna 93 through the directional coupler 90, the isolator 91, and the duplexer 92. Thereby, the output signal of the amplifier 80 is output using radio waves as a medium.
[0082]
The detector 100 includes a directional coupler 90. The output proportional signal is input, and the detector 100 Output detection signal To do. The filter 110 smoothes the detection signal of the detector 100 and outputs a smooth signal. The AD converter 120 performs analog-digital conversion on the smooth signal from the filter 110 and outputs a digital signal.
[0083]
The power controller 10h obtains a transmission power measurement period based on the timing signal from the digital modulator 10a. Further, the power controller 10h obtains the power level of the transmission signal (transmitted from the antenna 93) based on the digital signal from the A-D converter 120 for each transmission power measurement period, and calculates the power level as a target value. The variable gains of the gain control amplifiers 45 and 60 are updated so as to be close to.
[0084]
As the transmission power measurement period, a timing is adopted in which the variable rate of the first to third transmission signals is a constant rate, and the number of transmissions of the control signal and the first to third transmission signals is a constant number. The FIG. Then , Transmit power measurement period Is The output of the first to third transmission signals is prohibited (the variable rate is constant at “0”), and only the control signal is output. It is timing .
[0085]
In this case, since the combination of the first and second gain parameters βd and βc is constant, if the average transmission power transmitted from the antenna 93 remains constant, the digital signal from the AD converter 120 is , Become constant. Therefore, since a signal level corresponding to the target transmission power level is obtained as the digital signal, the memory 10k has a transmission power map having transmission power data for each target transmission power level. The It is sufficient to provide only one type, and the data storage capacity of the memory 10k can be reduced. Accordingly, the control algorithm for calculating the variable gain can be simplified.
[0086]
Here, since the power gain is different for each product of the multi-code communication device, each transmission power data corresponding to each target transmission power is stored in the memory 10k for each product when the multi-code communication device is manufactured. It is necessary to store it as a transmission power map. Therefore, in the first embodiment, the transmission power map The Since only one type is employed, it is possible to shorten the manufacturing time.
[0087]
In the first embodiment, the transmission power measurement period has been described as an example in which the output of the first to third transmission signals is prohibited and only the control signal is output. Not limited to this, if the variable rate of the first to third transmission signals is a constant rate and the transmission numbers of the control signal and the first to third transmission signals are respectively constant numbers, the digital The digital modulation method of the modulator 10a may adopt a fixed timing.
[0088]
(Second Embodiment)
In the first embodiment, the example in which the output of the first to third transmission signals is prohibited and only the control signal is output is described as the transmission power measurement period. Is lower than the power levels of the first to third transmission signals.
[0089]
For this reason, for example, a multi-code communication device is a base station of When located in the vicinity, the transmission power level of the antenna 93 is lowered by the transmission power control. Therefore, the smooth signal from the filter 110 may be below the lower limit value of the dynamic range of the A-D converter 120. Therefore, in the second embodiment, a period during which transmission in the compressed mode is prohibited (hereinafter referred to as a transmission prohibited period) is employed as the transmission power measurement period.
[0090]
FIG. 4 shows the operation of the second embodiment below. make use of explain. FIG. 4 is a timing chart of the first to third transmission signals (UP-LINK DPDCH) and the control signal (UP-LINK DPCCH).
[0091]
First, in the transmission prohibition period, the power controller 10h outputs the drive signal (RL1) to the relay 130 and outputs the drive signal (RL2) to the relay 140, thereby switching and driving the relays 130 and 140.
[0092]
Thus, the output terminal of the amplifier 80 and the input terminal of the directional coupler 90 90b And the gap between the detection terminal 91 of the directional coupler 90 and the input terminal of the detector 100 is opened. At the same time, the output terminal of the amplifier 80 is connected to the input terminal of the detector 100 through the relays 130 and 140. In Connected This The
[0093]
Here, in the transmission prohibition period, the digital modulator 10a outputs a high level signal, and the generators 10b and 10c output a constant (for example, “1”). For this reason, the digital filter 33 receives a constant DC voltage signal, and the digital filter 34 receives a constant DC voltage signal.
[0094]
A constant DC voltage signal is input as a real component I and an imaginary component Q of a constant DC voltage signal to the quadrature modulator 40 with a variable gain amplifier. Accordingly, since the real component I and the imaginary component Q are quadrature modulated by the multipliers 41 and 42 and the adder 44, the quadrature modulation signal has the same frequency component as the carrier wave signal (of the local oscillator 35). . However, the quadrature modulation signal is a frequency signal having a constant frequency.
[0095]
Here, the gain control amplifier 45 power-amplifies the quadrature modulation signal with a variable gain and outputs a transmission output signal. This transmission output signal is input to the multiplier 52 through the band pass filter 50, and the multiplier 52 frequency-converts the transmission output signal by the frequency signal of the local oscillator 36.
[0096]
Since the converted conversion frequency signal is input to the gain control amplifier 60 through the bandpass filter 51, the gain control amplifier 60 amplifies the power of the conversion frequency signal with a variable gain and converts the amplified signal into the bandpass filter 70 and the amplifier. The signal is input to the detector 100 through the relays 130 and 140 via 80. The filter 110 smoothes the detection signal of the detector 100 and outputs a smooth signal. The detection signal of the detector 100 is a constant frequency signal determined by the frequency signals of the local transmitters 35 and 36.
[0097]
The AD converter 120 performs analog-digital conversion on the smooth signal from the filter 110 and outputs a digital signal. Further, the power controller 10 h obtains the power level of the transmission signal based on the digital signal from the A-D converter 120.
[0098]
Here, in the transmission prohibition period, the gain control amplifiers 45 and 60 are controlled by applying a constant value as a control voltage. Therefore, if there is no temperature change or aging of the electronic components, each of the gain control amplifiers 45 and 60 is controlled. The output power level is constant. However, in reality, an error occurs in each of the above power levels due to heat generation of the equipment or environmental changes, and the difference between the output power level measured by the AD converter 120 and the ideal power level is obtained, and the temperature correction value is calculated. I'm calculating.
[0099]
Since the digital modulator 10a, together with the generators 10b and 10c, outputs an output signal at a constant level as described above, if the temperature of the electronic components from the multipliers 11, 13, 15, and 17 to the amplifier 80 is constant, The power level is constant. However, although the power level changes due to the temperature change of the electronic component, if this power level is known, the temperature change can be obtained.
[0100]
For this reason, in addition to storing each transmission power data for each target transmission power instructed from the base station, the transmission power map of the memory 10k stores the temperature correction value of the transmission power data due to the temperature change. Yes.
[0101]
Here, the power controller 10h is instructed by the base station after the end of the transmission prohibition period. Eye The transmission power data corresponding to the target transmission power is called from the memory 10k. The power controller 10h corrects the transmission power data with the temperature correction value, and outputs the corrected transmission power data to the gain control amplifiers 45 and 60 through the DA converter 10g.
[0102]
Thereby, the power controller 10h can obtain the power level of the transmission signal in the transmission prohibition period, and can update the variable gains of the gain control amplifiers 45 and 60 after the transmission prohibition period ends.
[0103]
As described above, since the power controller 10h obtains the power level of the transmission signal in the transmission prohibition period, the power level does not change depending on the combination of the first and second gain parameters βd and βc. Accordingly, since it is not necessary to prepare the transmission power map of the memory 10k corresponding to the combination of the first and second gain parameters βd and βc, an increase in the data holding capacity can be suppressed.
[0104]
Further, since the output signal (amplified signal) from the amplifier 80 is directly input to the detector 100 without passing through the directional coupler 90, the output signal of the amplifier 80 is attenuated by the directional coupler 90. Can be prevented. That is, the output signal of the amplifier 80 can be prevented from being attenuated by the amount of the coupling capacitance of the directional coupler 90.
[0105]
Furthermore, if the constants output from the generators 10 b and 10 c are varied, the level of the smooth signal from the filter 110 can be made to correspond to the dynamic range of the AD converter 120. Further, since the power level of the transmission signal is obtained during the transmission prohibition period, it is not necessary to set the target value of the transmission power at this time, and the digital signal of the A-D converter 120 can be freely set.
[0106]
Furthermore, an output terminal of the amplifier 80 and an input terminal of the directional coupler 90 are provided by the relay 130. 90b Therefore, it is possible to prevent the output of the amplifier 80 from being transmitted from the antenna 93 using radio waves as a medium.
[0107]
In implementing the present invention, the first and second embodiments may be combined. Furthermore, in implementing the present invention, high frequency switches or semiconductor relays may be employed as the relays 130 and 140. Since the detection signal of the detector 100 is a constant frequency signal as described above, for example, as shown in FIG. 5, the detector 100 can be realized with a simple configuration using only a capacitor. Furthermore, in implementing the present invention, the total number of transmission signals (DPDCH) and control signals (DPCCH) is not limited to four, and may be two or four or more.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electric circuit configuration showing a part of a transmitter according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing an electric circuit configuration showing the remainder of the transmitter in the first embodiment.
FIG. 3 is a diagram for explaining an operation in the first embodiment.
FIG. 4 is a diagram for explaining the operation of a transmitter according to a second embodiment of the present invention.
FIG. 5 is a diagram showing details of a filter.
FIG. 6 is a block diagram showing an electric circuit configuration showing a conventional transmitter.
FIG. 7 is a block diagram showing an electric circuit configuration showing a part of the transmitter.
FIG. 8 is a block diagram showing an electric circuit configuration showing the rest of the transmitter.
9 is a diagram for explaining the operation of the filter shown in FIG. 6. FIG.
10 is a diagram for explaining the operation of the filter shown in FIG. 8. FIG.
11 is a diagram for explaining the operation of the filter shown in FIG. 8. FIG.
12 is a diagram for explaining the memory shown in FIG. 8; FIG.
[Explanation of symbols]
10h ... power controller, 10k ... memory, 12 ... A-D converter,
45, 60 ... Gain control amplifier.

Claims (8)

First spreading means (11, 13 , 15 ) for spectrum-spreading at least one transmission signal having a variable rate with a transmission code and outputting a transmission spread signal, and spectrum-controlling a fixed-rate control signal with a control code Second spreading means (17) for outputting a control spread signal;
First multiplying means (12, 14, 16) for multiplying the transmission spread signal by a first coefficient to obtain a transmission multiplication signal, and multiplying the control spread signal by a second coefficient to obtain a control multiplication signal Second multiplication means (18);
Setting means (10c) for keeping the sum of the powers of the transmission multiplication signal and the control multiplication signal constant, and setting the first and second coefficients so as to match the powers;
Orthogonal modulation means (41 to 44) for orthogonally modulating the transmission multiplication signal and the control multiplication signal to output an orthogonal modulation signal;
Transmission output variable means (45, 60) for amplifying the quadrature modulation signal with a variable gain and outputting a transmission output signal;
A memory (10k) that stores a transmission power map when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a fixed number;
The power level of the transmission output signal is detected at each timing at which the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a constant number, and this power level is detected as a target of the transmission power map. A spread spectrum transmitter comprising: update means (10h) for updating the variable gain so as to approach the value. 2. The spread spectrum transmission according to claim 1, wherein the update unit sets a timing at which the output of the transmission signal is prohibited and only the control signal is output as the detection level of the power level. Machine. The spread spectrum transmitter according to claim 1, wherein the updating unit sets a timing at which the digital modulation scheme of the transmission signal is the same as the detection timing of the power level . First spreading means (11, 13, 15) for spectrum-spreading at least one transmission signal having a variable rate with a transmission code and outputting a transmission spread signal, and spectrum-controlling a fixed-rate control signal with a control code Second spreading means (17) for outputting a control spread signal;
First multiplying means (12, 14, 16) for multiplying the transmission spread signal by a first coefficient to obtain a transmission multiplication signal, and multiplying the control spread signal by a second coefficient to obtain a control multiplication signal Second multiplication means (18);
Setting means (10c) for keeping the sum of the powers of the transmission multiplication signal and the control multiplication signal constant, and setting the first and second coefficients so as to match the powers;
Orthogonal modulation means (41 to 44) for orthogonally modulating the transmission multiplication signal and the control multiplication signal to output an orthogonal modulation signal;
Transmission output variable means (45, 60) for amplifying the quadrature modulation signal with a variable gain and outputting a transmission output signal;
The power level of the transmission output signal is detected at each timing when the variable rate is a constant rate and the number of transmissions of the control signal and the transmission signal is a constant number, and the power level is brought close to a target value. Updating means (10h) for updating the variable gain;
The update unit is the as the detection timing of the power level, spread-spectrum transmitter you characterized in that digital modulation system of the transmission signal to set the timing is the same. First spreading means (11, 13 , 15 ) for spectrum-spreading at least one transmission signal having a variable rate with a transmission code and outputting a transmission spread signal, and spectrum-controlling a fixed-rate control signal with a control code Second spreading means (17) for outputting a control spread signal;
First multiplying means (12, 14, 16) for multiplying the transmission spread signal by a first coefficient to obtain a transmission multiplication signal, and multiplying the control spread signal by a second coefficient to obtain a control multiplication signal Second multiplication means (18);
Setting means (10c) for keeping the sum of the powers of the transmission multiplication signal and the control multiplication signal constant, and setting the first and second coefficients so as to match the powers;
Orthogonal modulation means (41 to 44) for orthogonally modulating the transmission multiplication signal and the control multiplication signal to output an orthogonal modulation signal;
Transmission output variable means (45, 60) for amplifying the quadrature modulation signal with a variable gain and outputting a transmission output signal,
At the prohibition timing at which the setting of the first and second coefficients is prohibited, the orthogonal modulation means outputs a frequency signal having a constant frequency as the orthogonal modulation signal to the transmission output variable means,
A spread spectrum transmitter comprising: an updating means (10h) for detecting a power level of the transmission output signal at each prohibition timing and updating the variable gain in accordance with the power level. An antenna (93) for transmitting the transmission output signal using radio waves as a medium;
Switch means (130, 140) for blocking or connecting the front of the antenna,
6. The spread spectrum transmitter according to claim 5 , wherein the updating means controls the switching means so as to cut off the output to the antenna at the prohibition timing. The first multiplication means outputs the transmission spread signal at a constant level at the prohibit timing,
The spread spectrum transmitter according to claim 6 , wherein the second multiplying unit outputs the control spread signal at a constant level at the prohibit timing. The update unit is the said variable rate is a constant rate, and the transmission speed of the control signal and the transmission signal for each timing respectively fixed number, the 5 to claim and updates the variable gain The spread spectrum transmitter according to any one of 7 .

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